Here is an excerpt from an article by the author in The New York Times:

What lessons can we draw from history? The most straightforward: take environmental problems seriously. They destroyed societies in the past, and they are even more likely to do so now. If 6,000 Polynesians with stone tools were able to destroy Mangareva Island, consider what six billion people with metal tools and bulldozers are doing today. Moreover, while the Maya collapse affected just a few neighboring societies in Central America, globalization now means that any society’s problems have the potential to affect anyone else. Just think how crises in Somalia, Afghanistan and Iraq have shaped the United States today.

Other lessons involve failures of group decision-making. There are many reasons why past societies made bad decisions, and thereby failed to solve or even to perceive the problems that would eventually destroy them. One reason involves conflicts of interest, whereby one group within a society (for instance, the pig farmers who caused the worst erosion in medieval Greenland and Iceland) can profit by engaging in practices that damage the rest of society. Another is the pursuit of short-term gains at the expense of long-term survival, as when fishermen overfish the stocks on which their livelihoods ultimately depend.

History also teaches us two deeper lessons about what separates successful societies from those heading toward failure. A society contains a built-in blueprint for failure if the elite insulates itself from the consequences of its actions. That’s why Maya kings, Norse Greenlanders and Easter Island chiefs made choices that eventually undermined their societies. They themselves did not begin to feel deprived until they had irreversibly destroyed their landscape.

The other deep lesson involves a willingness to re-examine long-held core values, when conditions change and those values no longer make sense. The medieval Greenland Norse lacked such a willingness: they continued to view themselves as transplanted Norwegian pastoralists, and to despise the Inuit as pagan hunters, even after Norway stopped sending trading ships and the climate had grown too cold for a pastoral existence. They died off as a result, leaving Greenland to the Inuit. On the other hand, the British in the 1950’s faced up to the need for a painful reappraisal of their former status as rulers of a world empire set apart from Europe. They are now finding a different avenue to wealth and power, as part of a united Europe.

History can be a great teacher. Jared Diamonds books are a great starting point to understanding of how we got where we are.